1. Field of the Invention
The present invention relates to barcodes and, more particularly, to a barcode having a first basic stored information structure and a second enhanced stored information structure.
2. Description of the Prior Art
U.S. Pat. No. 5,153,418 discloses multiple resolution machine-readable symbols. Barcodes are used in many applications for the identification, tracking, and tracing of objects, letters, or packages. Some applications require only very basic information about an object (identity or destination), while other applications require detailed information about an object (e.g., postage paid, origin address, postage meter number, sender, addressee, destination address, weight, date, contents, batch number). Barcodes are also used extensively for the identification of objects for sale; for example, the Universal Product Code (UPC), and in many other applications. Such barcodes, in principle, could be expanded to include data about batch numbers, production dates, or expiration dates to aid in product recalls and rotation of product inventory.
Introduction of additional barcode information is hindered by several factors including real estate available on the object for barcoding; existing standardized barcode specification precluding expansion (e.g., Postnet is set as 12 digits); resolution of existing barcode readers and printers; expense and logistics to retrofit existing readers and printers; and need for barcoding schemes to conform to the least common denominator user.
Currently the solution for adding additional information in a barcode is to retain the old scheme barcodes (e.g., PostNet) for a period of time longer than desired. When the need becomes acute, then new barcode schemes (for instance PLANET and Universal Postal Union (UPU)/Remote Video Encoding (RVE) barcode supplementary barcodes) will be added to the same envelope. This approach is especially unsatisfactory, because it drives the adoption of independent non-integrated barcodes rather than driving the adoption of coordinated integrated barcoding solutions with a clear upward migration path. In the retail market place, the problems associated with expansion of barcodes and introduction of new barcode reader standards have precluded the use of these barcodes to aid in the Universal Product Code (UPC) tracking of expiration dates or product batch numbers.
Barcodes also carry heavy overhead costs. Because data read from barcodes is often affected by errors due to printing or poor handling, various error detection and correction solutions are applied to correct the read errors. Error detection mechanisms are generally based on the idea that a mathematical algorithm is applied to the data received (read) and, if the result indicates inconsistencies, then some of the data is used to recover the missing information. Current implementations have the useful data payload, error detection, and error correction transmitted (read) as part of a “homogeneous” process. Often, the three kinds of data are intermixed. When there is no loss of data (no read error), the error correction information never gets used. In such instances, the resources necessary to carry, read, and process that portion of data are “wasted”. These resources are real estate on the label, scan time, processing time, storage for additional information, etc. The error correction and overhead information component of the total data stored in a barcode, depending on the level of redundancy required by the application, may exceed fifty (50%) percent.